Phase and amplitude control of switching from positive to negative dispersion in superconducting quantum circuits

We study the absorption and dispersion properties of the three-level ΔΔ-type superconducting fluxonium circuit, in which each atomic transition is respectively driven by a coherent classical field. The results show that the absorption and dispersion spectra depend strongly on the relative phase and intensities of the applied fields. When the relative phase is changed from ππ/2 to 3ππ/2, the switching from positive to negative dispersion arises, which can also be obtained via adjusting the relative intensities of the classical fields. Our scheme shows that the dispersion switching effect could be achievable for microwave pulse interacting with the superconducting fluxonium qubit.